I have been using synaptic package manager for general information temporarily

I just would not recommend installing anything critical with it.
Synaptic is good for looking up and finding out about software and the GUI is tempting because it is right there.
The problem with critical system installs is that you are running KDE and that can lead to issues unforeseen.

Any eta as to when packagesearch will be updated to accept new apt-get?

No real eta (anymore), but maybe end of this week or after he has removed certain functionality. The problem isn't the new apt version (it just is a visible indication), the package in its current form didn't build anymore since august last year. That's not acceptable.